I have 5 of them so far. 4 are the ZA-5's and one a ZA-3 that cameraland had on sale. I've only had one that had any sort of problem - the ocular wouldn't focus for my eyes - and Minox took care of it.
3 of them have some sort of BDC on them. Tff caribou is correct, test them for yardage at the range.
The ZA-5's are the better of the two and the more expensive of the two. Clarity and sharpness of them is on par with a Zeiss Conquest HD 5 I have.
Though not 'turret-turners', the adjustments are fairly crisp on them, not a true 'click' for those that like to turn turrets though.
Boxing a target showed them to be very consistent with a good return to zero.
The ZA-3 I have is very close with an older VX-3 I have though I do note it's a few minutes later/earlier at low light. View is crisp and sharp for a scope I paid $100 for. I haven't had a chance to test the BDC on this one yet, it's on a pick-up 30-06 I snagged right after Thanksgiving and all I've done is sight it in so far. This rifle is more of a truck-gun/loaner gun for me so it probably won't get used all that much.
All in all, the Minox is becoming a go-to for me for new optics. As my old Leica's finally bail on me, I'll replace them with the Minox.
Pay it forward - Kids are the future.
Rifles are similar to boats and young women...there's no end to how much money you can pour into them without making them any more useful.